The Ministry of Health and Family Welfare on Monday decided to conduct a population-based sero survey in select districts of the country with an aim to monitor the trend in the prevalence of SARS-CoV-2 infection.
"The ICMR/NCDC is going to conduct a population-based sero survey in selected districts of the country. The aim is to monitor the trend in the prevalence of SARS-CoV-2 infection at the district level. Throat/nasal swabs to be collected for RT-PCR tests," said the ministry.
This surveillance will be in addition to the routine testing as per current testing guidelines, the ministry said.
It further stated there is a need to establish systematic surveillance for SARS-CoV-2 infection in all districts of the country.
The surveillance unit will consist of 10 health facilities including six public and four private ones from each district.
For the population groups, among the low-risk population, outpatient attendees (non-ILI patients) and pregnant women will be tested while among the high-risk population healthcare workers will be surveyed, the ministry informed.
As many as 100 samples per week and 400 samples per month will be collected from selected districts among high-risk population.
While, among the low-risk population, 50 samples will be collected per week and 200 per month of outpatient attendees (non-ILI patients), as well as of pregnant women.
In total, 200 samples per week and 800 samples per month will be collected.
For laboratory and pooling, the ministry said, samples should be tested in a onetime pool of 25. The results of this sample pooling is only for surveillance purposes. It should not be used for the diagnosis of individual patients.
"In addition to throat/nasal swabs, blood samples should be collected for detecting IgG antibodies for ELISA testing. In subsequent rounds, IgG ELISA based testing of serum samples will replace RT-PCR based testing for surveillance purpose," the ministry added.
The data will be analysed locally for action using standard indicator formats. Indicators for person, place, time and trend analysis will be made.
The method will be jointly implemented across the country by the district and state health administrations, Integrated Disease Surveillance Programme (IDSP), National Centre for Disease Control (NCDC), Indian Council of Medical Research (ICMR) institutes, community medicine departments of medical colleges and public health institutes.
( With inputs from ANI )